Indoor air pollution is also a very potent and dangerous. For example, one study in California found that the levels in pollution indoors is 25%-62% greater than the levels of pollution outdoors. This is a significant number because people can spend as much as 80%-90% of their lives indoors, exposed to the pollution (Indoor Air Pollution). One dangerous form of pollution is radon. Radon is a naturally occurring, radioactive gas that accumulates in basements and below-ground structures (Indoor Air Pollution). Other, less severe forms of pollution are smoke, cooking and heating appliances, and fumes from paint, and other household chemicals (Indoor Air Pollution). Prolonged exposure to theses pollutants can cause several short and several long-term effects. Some short term effects include irritation of eyes, nose, and throat with a tendency to promote asthma (Indoor Air Pollution).